module 4 lesson 7 interpret area models to form rectangular arrays
TRANSCRIPT
Draw Rectangles First of all, Make sure you have Grid Paper.
Draw a rectangle that has an area of 6 square units.
Draw a rectangle that has an area of 10 square units.
Draw a rectangle that has an area of 12 square units.
Draw a rectangle that has an area of 16 square units.
Draw a rectangle that has an area of 24 square units.
Draw a rectangle that has an area of 35 square units.
Thumbs up when you’re done!
Draw Rectangular Arrays
Draw a 4 x 2 rectangular array using the squares on your grid paper.
How many square units are in your array?
8 square units.
Draw Rectangular Arrays
Draw a 6 x 2 rectangular array using the squares on your grid paper.
How many square units are in your array?
12 square units.
Draw Rectangular Arrays
Draw a 4 x 3 rectangular array using the squares on your grid paper.
How many square units are in your array?
12 square units.
Draw Rectangular Arrays
Draw a 6 x 4 rectangular array using the squares on your grid paper.
How many square units are in your array?
24 square units.
Concept Development • Work with people at your table (you can have a group size
of 2 – 3)• Make sure each group has equal amounts of centimeter
tiles and square inch tiles. • Decide with your partner (group) how to arrange your tiles
to make the same shape rectangle. • Then create those rectangles with your pieces (cm cubes,
and square inch tiles)• Trace or draw a picture of your rectangles. • THUMBS UP WHEN YOU’RE FINISHED.
Time to think!• You and your partner(s) made the same shape rectangle.
Is there area also the same?• Why or why not?• Write the area of your rectangle on your board.• I will show you 1 square meter on the board• Suppose you used 12 square meter tiles to make your
rectangle. Would this rectangle have a BIGGER area or a smaller area compared to your rectangle?
• BIGGER
Still thinking…• Now I’m going to draw a square foot on the board. How
would your rectangle compare if you make it from 12 square feet?
•It would be bigger than 12 square inches or centimeters, but smaller than 12 square meters.
• How about this pad of sticky notes? • Still bigger than square inches or centimeters, but smaller than square feet or centimeters.
THE BIG QUESTION• Why is it important to label the UNIT when you’re talking
about area?• The area changes if the unit is small or big• If you do not know the unit then you really don’t know the
size of the area.
Relate area to multiplication to draw rectangular arrays• We will draw a rectangular array with an area of 18
square centimeters. • How might we find the side lengths? • Work with your partner to make a list of multiplication facts
that equal 18. • (1x18, 18x1, 2x9, 9x2, 3x6, 6x3)• Use a ruler to create a 3cm x 6cm rectangular array. • After drawing your squares, check your work by skip-
counting the rows to find the total number of tiles you drew.
• Thumbs up when you’re done.
• Erase the inside grid lines of your 3 x 6 rectangular array. • The empty rectangle with the labeled side lengths is
called the area model. How can you find the total area just using the labeled side lengths?
3cm
6 cm
What is the total area of this rectangle?
Suppose the unit In this area model is in inches.
The side lengths of thisModel are not labeled.
Do we need to drawgrid lines to find the area Of this rectangle?
What is the area of thisArea model?
8 square inches